title: Role of vitamin D in maternal skeletal changes during pregnancy and lactation: a histomorphometric study.
abstract: The effect of vitamin D on bone changes during the reproductive cycle in female rats has been investigated. One group of female rats was maintained on a vitamin D-deficient diet and another group of a vitamin D-replete diet from weaning. Both groups were mated with normal males and changes in their bones were determined histomorphometrically during pregnancy, lactation, and after weaning. All vitamin D-deficient rats had bone changes typical of rickets. Pregnancy caused significant reductions in mineralized tissue of trabecular and cortical bone in the vitamin D-deficient rats. Lactation caused further significant reductions in mineralized tissues of cortical and trabecular bone in both the vitamin D-deficient and vitamin D-replete animals, with the greatest changes seen at weaning. Some restoration of mineralized tissues occurred following weaning. There was an increase in tetracycline-labeled bone surface in the vitamin D-replete animals during lactation, likely due to an increase in bone formation rates. In the vitamin D-deficient animals during lactation, there was a decrease in tetracycline-labeled bone surface, likely due to severely depressed bone mineralization. These results indicate that the mobilization of calcium from bone to maintain pregnancy and lactation occurs by a mechanism independent of vitamin D.
mesh_terms: D000818:Animals; D001842:Bone and Bones / Q000187:drug effects / Q000502:physiology* / Q000503:physiopathology; D004838:Epiphyses / Q000187:drug effects / Q000502:physiology; D005260:Female; D007774:Lactation / Q000187:drug effects*; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000187:drug effects*; D051381:Rats; D014807:Vitamin D / Q000494:pharmacology*; D014808:Vitamin D Deficiency / Q000503:physiopathology*
chemical_list: D014807:Vitamin D